DAYTONA BEACH, FL (CBSNews.com) - A pregnant mother was talking about demons but seemed lucid to police who were asked to check on her just hours before she drove a minivan into the Atlantic Ocean with her three children trapped inside the vehicle, authorities said Wednesday.

Horrified onlookers said the two older children, ages 9 and 10, fought frantically for their lives as the black Honda Odyssey became nearly submerged in the surf Tuesday afternoon.

Tim Tessseneer was driving with his wife behind the minivan just before the woman drove into the waves.

"We saw a kid sitting on the mother's lap trying to pull the steering wheel out of her hand and turn it away from the water and the kid in back was just screaming, 'Help us, help us, our mom is trying to kill us,"" Tesseneer said.

Beach-goers heard the two children screaming for help. They pulled the 9- and 10-year-old to safety before realizing a 3-year-old was still strapped into her seat. She, too, was safely brought to shore. The mother also got out OK.

Tesseneer and another man were the first to reach the minivan, which was drifting deeper and deeper into the Atlantic.

"The kids are screaming, 'There's a baby! There's a baby!'," Tesseneer recalled. "I get back to the van, and by this time a couple of lifeguards have made it down to us, and come to find out there's a baby still strapped in the seat, but we got her. "

Dramatic video of the terrifying incident shows a lifeguard carrying the youngest child away from the vehicle.

The mother, identified as Ebony Wilkerson, got out of the minivan through a window, witnesses said.

"She dove out the window, the driver's window ... just belly-flopped into the water," Tesseneer said.

The woman walked away without trying to do anything to aid her children.

"Instead of trying to get the doors open, she just walked back up shore," said another witness, Taylor Quintin.

Volusia County Sheriff Ben Johnson praised rescuers for getting to the family so fast.

"The waves were strong, the water was cold, they got in the water and got them out of their quickly," Johnson said. "If it had been minutes longer, the outcome probably would have been different."

The family members were checked out at a hospital and Wilkerson was being given a psychiatric evaluation. The children were turned over to the Florida Department of Children and Families, the sheriff's department said.

Just hours before Wilkerson drove into the surf, her sister had called 911. The sister told police Wilkerson had fled an abusive husband in South Carolina and was talking about demons.

Police said that talked to Wilkerson and noticed that she was acting strangely but did not see a reason to take her into custody.

"Her sister had called dispatch and told them that she had been talking about demons that day before she left the house," Daytona Beach Police Chief Mike Chitwood said Wednesday, according to the The Daytona Beach News-Journal. "She was not concerned about the children because the sister said she would never harm her children. But she did say (Wilkerson) had been talking about demons and seemed a little off."

A day earlier, Wilkerson had gone to an area medical center to voluntarily check herself in, but then decided against it and walked out, the chief said.

"When we spoke with her, she was lucid," the chief said, according to the newspaper. "The children were in the back seat, they were buckled in and were not in distress."

Just a few hours later, the mother drove with her children into the water.

Beach safety officers said the minivan was being driven recklessly southbound on the beach when it suddenly turned eastward into the ocean.

"My friend pointed out that there was a car getting really close to the beach, and actually started driving on the water," Quintin said.